The present invention relates to the field of security in data processing and electronic commerce and particularly to methods and apparatus for secure storage and transfer of electronic funds and other value data.
Data processing systems have been used to store and transfer electronic funds, encryption codes and other value data. To deter theft of the value data, data processing systems have employed devices having some form of security control (security controlled devices). An example of such data processing systems are electronic funds systems where the security controlled devices are smart cards. Another example of such data processing systems are cryptographic systems where the security controlled devices are stores for encryption codes and algorithms for encrypting data. While cryptographic techniques have been used to protect communications to and from security controlled devices, cryptology alone does not protect against the theft of the security controlled devices themselves. Electronic funds, encryption codes and other value data can be stolen from a data processing system by stealing the security controlled devices themselves thereby stealing the value data contained therein or associated therewith.
In the field of electronic commerce, wire transfers are one electronic method for the transfer of value that involves the transfer of funds from one trusted party to another. In a wire transfer, one party makes a debit book entry and the other party makes a credit book entry as a result of value data electronically sent from one party to another in accord with preestablished procedures agreed to by the parties. The wire transfers are usually subject to clearing operations to verify that the debit and credit entries have been made correctly and to reconcile the accounts between the parties. The security of the wire transfer of funds is higher if the value data transfer that implements the wire transfer is encrypted using electronic encryption/decryption devices, codes or algorithms. Such electronic encryption/decryption devices or the devices that store the codes or algorithms need to be security controlled devices since, if these devices are stolen, the security of the wire transfers is compromised.
In the field of electronic commerce, electronic cash is another electronic method for the transfer of value that involves the transfer of funds from one party to another. Electronic cash methods include two types of transfers, namely certificated value and net value transfers.
For the certificated value type of electronic cash, an issuer generates electronic value or transaction records, generally cryptographically encoded and signed, that represent distinct amounts of value. These electronic value or transaction records may be passed from one electronic cash device to another electronic cash device. For example, the transfer of funds occurs from a small portable electronic cash device (smart card) held by one party to an electronic cash device held by another party. In one form common to consumers, smart cards are portable cards similar in form and size to common credit or debit cards. In an alternate miniature form, the size is reduced to contain small contact area and internal electronics only. Typically, a smart card is issued by the issuer and dispensed to a first party (for example, a purchaser) where the card is pre-loaded or subsequently loaded with stored electronic value or transaction records (certificates), the electronic value record (certificate) is passed by the first party to an electronic cash device of another party (for example, a merchant) and, eventually, the electronic value record (certificate) is returned to the issuer by the other party for redemption in the amount of the electronic value record (certificate). Usually, electronic cash devices used by merchants, banks and other financial institutions are under the administrative and technical control of an issuer. Electronic cash devices that contain electronic value records need to be security controlled devices since, if these devices are stolen, the amount of money represented by the electronic value record (certificate) can be permanently lost.
For the net value type of electronic cash, the electronic value is represented by the net amount stored in an electronic device without need for further external accounting. Specifically, in the net value type of electronic cash, the value is not represented by electronic certificates or transaction records that must be transferred and redeemed from an issuer. The net value type of electronic devices are called value stores and each is capable of storing a net amount of value that reflects the accumulated aggregate of value transfers from and to that value store from other value stores.
Value stores can be implemented using cards (smart cards) that are similar to those used for the certificated value type of electronic cash except that the rules controlling the transfer of value are appropriate for the net value type of electronic cash. In an electronic funds system, merchants, banks or other institutions are the issuers that issue value stores (in the form of smart cards) to customers. The issuer in turn retains value stores capable of performing transactions with the value stores of its customers and others. An issuer may require tens or hundreds of value stores to conduct transactions with the value stores in the possession of its customers or correspondent institutions. Electronic value stores need to be security controlled devices since, if these devices are stolen, the amount of money represented by the electronic net value stored can be permanently lost.
Physical security is a typical method of protecting security controlled devices. In electronic funds environments, the individual security controlled devices are small devices that are easily concealed and moved. If the security controlled devices are value stores in a bank or other institution, the value stores are frequently contained in locked and guarded vaults with stringent access controls to the vaults. However, such physical security alone is increasingly difficult and insufficient as security controlled devices are further miniaturized and as security controlled devices are distributed to remote locations and institutions without vaults.
Because of the limitations and high costs of physical security, various methods have been provided to electronically enable and disable security controlled devices so that in the disabled state, they offer a reduced value to potential thieves. Previous systems have reduced the incentive for theft by manually removing value data from security controlled devices or by using secure operating modes for transfers involving security controlled devices.
The secure operating modes for security controlled devices are frequently manually implemented and frequently employ a data key such as a Personal Identification Number (PIN). In one commonly used implementation, a value store may be locked to inhibit the normal action of removing electronic funds so that restoration of the ability to remove electronic funds from the value store that is disabled or locked requires use of a previously determined PIN to unlock the value store. The PIN number may or may not be changeable depending on the design of the value store. Procedures are required for creation and distribution of PIN numbers, and of course the consequences of performing incorrect security procedures renders the value store not accessible by the ordinary means.
In another PIN implementation, a PIN number is required for the lock operation as well as for the unlock operation. The lock and unlock PIN numbers may be the same or different and they each may be fixed or changeable. In this variation, transaction durations are increased in order to accommodate the lock and unlock operations and sustainable transaction rates to value stores are reduced because of the PIN operations that must be performed. Difficulties resulting from the distribution of and procedures for use of PIN numbers remain present in such implementations.
In a high-security variation, a PIN number unique to the lock operation must be supplied with the lock operation and again to reverse the lock operation. In this variation, transaction duration is increased and sustainable transaction rate to a value store is reduced because of the additional restrictions on the PIN operations. This variation is sometimes called a single-use key method. Difficulties from distribution of and procedures for use of PIN numbers are more complicated.
In another high-security variation, the value store requires the presentation of the PIN number before every occurrence of some or all operations, but the relocking is automatic after each operation. In this variation, compared to the previous high-security variation, the transaction duration is slightly decreased and the sustainable transaction rate to a value store is slightly increased because a manual lock operation is not required after each operation.
Methods of unlocking value stores are varied. A first (primary) method of unlocking value stores employs an unlocking sequence in which a first unlocking key (primary unlocking key) is used to unlock locked value stores. The unlocking key must be available from some source. A second method of unlocking value stores, used in addition to the first method, operates independently of any requirement for knowledge of the primary unlocking key.
This second method, sometimes called a backdoor method, may be used, for example, by a security manager to unlock a value store when the primary key to unlock that value store has been lost, intentionally erased, or never supplied. A backdoor method may be required to unlock a value store where an security mechanism internal to the value store automatically locks the value store in response to an external security threat. An example of such a security threat exists where repeated unsuccessful attempts to unlock a locked value store occurs and the repeated unsuccessful attempts are detected by the value store itself. While backdoor methods of unlocking provide flexibility, strong operational security is required to protect against fraudulent use of a backdoor method.
The aforementioned security procedures have the following general disadvantages:
Methods which disable operation of security controlled devices generally are effective only for security controlled devices that are not in use since value stores that are locked cannot be used to dispense electronic funds. PA1 In order to be effective, rigorous training and discipline of staff is required. If the distribution of PIN numbers is not well controlled, PIN numbers will be unavailable when needed. PA1 The knowledge of the methods for enabling and disabling the security controlled devices must be widespread among authorized agents. For example, if a large staff like that in the institutional environment of a bank requires access to security controlled devices, then the keys (PIN numbers) and the knowledge of how to enable and disable value stores must be imparted to or available to that large staff. The process of generating, storing and distributing the keys makes the system susceptible to invasion for theft and hence reduces security. PA1 The security processing can be time consuming. For example, the process of locking or unlocking a value store may require multiple manual operations. PA1 Procedures become progressively more onerous as the number of security controlled devices in a system increases. PA1 Handling small devices that are easily concealed and may have considerable value is a temptation for casual theft. PA1 The use of manual key (PIN) operations causes a transaction duration to increase undesirably and causes the sustainable transaction rate to a security controlled device (value store) to be reduced undesirably. These increases and decreases result because, prior to value data transfer, an unlock operation must be performed, and subsequent to the value data transfer, a lock operation must be performed. The prior and subsequent operations consume communications time and processing time including the time required to generate commands and perform the operations for validating and otherwise processing keys (PIN's). PA1 The locking sequence obtains locking keys from the processor unit and applies the locking keys to lock the security controlled devices. PA1 The locking sequence includes discarding the locking keys after the security controlled device is locked so that the locking key does not remain in the security enclosure. PA1 The locking sequence includes obtaining locking keys from the client system and applying the locking keys to lock the security controlled devices PA1 The processor unit randomly generates the locking key and discards the locking key after the security controlled device is locked so that the locking key does not remain in the security enclosure. PA1 The security controlled device includes means for sensing a security breach and for responsively automatically locking the secured controlled device. PA1 The security controlled devices include unlocking means for unlocking the security controlled devices to permit transfers of data from the security controlled devices. PA1 The unlocking means responds to an unlocking sequence for unlocking the security controlled devices. PA1 The unlocking sequence includes a primary unlocking sequence and a backdoor unlocking sequence. PA1 The locking sequence obtains locking keys from the processor unit, applies the locking keys to lock the security controlled devices and discards the locking keys after the security controlled devices are locked so that the locking keys do not remain in the security enclosure and wherein each of the security controlled devices includes unlocking means responsive to a backdoor sequence for unlocking the security controlled devices to permit transfers of data from the security controlled devices.
While conventional PIN methods can improve security for an individual value store, they do not protect other values stores that may be similarly situated and may soon come under attack.
While the forgoing disadvantages and limitations exist when the agents are individuals interacting with one or a small number of value stores, the problems are magnified in a setting where there are many agents sharing access to many value stores, particularly when the value stores are unattended.
Practical systems tend to group value stores in larger enclosures such as shelves and racks for shelves. These larger enclosures add to the complexity of processing and increase the security risk at least because of the greater numbers of value stores that are concentrated in a common location.
In light of the problems of prior art systems, there is a need for improved methods and apparatus for secure electronic storage, transfer and other processing of value data using security controlled devices and particularly for secure repositories which remove incentives for theft.